1. Field of the Invention
2. Description of the Prior Art
The present invention relates to a device for contactless current generation, in particular bicycle dynamo, on a rotatable counter element, in particular wheel rim, with at least one movably mounted rotor element having at least one magnet, and at least one coil, in the at least one winding of which a current can be induced by the magnet, which moves together with the rotor element, said current being usable to operate a consumer, wherein the rotor element is movable by magnetic interaction with the counter element, characterized in that the rotor element and the counter element have different axial lines, and, in an operative position, the rotor element is designed to generate at least one magnetic field on the basis of an eddy current in the conductive counter element, which forms an uninterrupted circular path, in such a manner that, by means of continuous relative movement between the counter element and rotor element, eddy current fields which are continuously opposed to one another and have oppositely polled magnetic fields to one another are induced in the counter element and the rotor element is thus moved together with the counter element with an eddy current gearing being formed. Furthermore, the invention relates to a vehicle lighting system and to a bicycle, each with a corresponding device for current generation.
There is a variety of different bicycle dynamo types for current generation for bicycle lamps. This may be for example, sidewall dynamos or roller dynamo, whose friction wheel runs along at the side panel and/or on the bearing surface of the tire.
The disadvantage of these dynamo types is in the bad efficiency and the significant braking effect caused by the necessary high contact pressure at the tire as well as in weather dependence during mud, wetness and snow, as well as in often disturbing noise.
Beyond that for example hub dynamos are well-known.
Hub dynamos are directly integrated into the wheel hub and usually have a gear. They are independent of the weather and provide enough electrical power, but have the disadvantage of higher weight, which is an exclusion criterion in particular in sports wheels, and they can be upgraded only at great expense by replacing the wheel hub.
Classical contactless dynamos require additional magnets or magnetic rings in the spokes, which induce a voltage in fixed-mounted coils.
They run without contact and therefore noiseless and only have little braking effect. In order to achieve adequate power many additional magnets must be anchored manually in the spokes, which again is an exclusion criterion for sports wheels.
In addition, generators have been developed, in which one or more magnets within a component attached to the frame or the wheel fork are set in motion, in that the magnets or metal pieces mounted on the (on the rim or spokes) produce a directed magnetic interaction when passing the component.